Tech Tips
Each ECM terminal's normal voltage is shown in the table below.
In the table, first follow the information under "Condition". Look under "Symbols (Terminal No.)" for the terminals to be inspected. The standard voltage between the terminals is shown under "Specified Condition".
Use the illustration above as a reference for the ECM terminals.
| Symbols (Terminal No.) | Wiring Color | Terminal Description | Condition | Specified Condition |
|---|---|---|---|---|
| BATT (E14-3) - E1 (E17-1) | L - BR | Battery (for measuring battery voltage and for ECM memory) | Always | 9 to 14 V |
| +BM (E14-7) - E1 (E17-1) | R-W - BR | Power source of throttle motor | Always | 9 to 14 V |
| IGSW (E14-9) - E1 (E17-1) | B-O - BR | Ignition switch | Ignition switch ON | 9 to 14 V |
| +B (E14-1) - E1 (E17-1) | B - BR | Power source of ECM | Ignition switch ON | 9 to 14 V |
| +B2 (E14-2) - E1 (E17-1) | B - BR | Power source of ECM | Ignition switch ON | 9 to 14 V |
| OC1+ (E17-17) - OC1- (E17-16) | L-B - R-B | Camshaft timing oil control valve (OCV) | Ignition switch ON | Pulse generation (see waveform 1) |
| OC2+ (E17-15) - OC2- (E17-14) | P-L - Y | Camshaft timing oil control valve (OCV) | Ignition switch ON | Pulse generation (see waveform 1) |
| MREL (E14-8) - E1 (E17-1) | W-G - BR | MAIN relay | Ignition switch ON | 9 to 14 V |
| VC (E15-23) - E2 (E15-28) | LG-B - BR | Power source for sensors (specific voltage) | Ignition switch ON | 4.5 to 5.5 V |
| VG (E15-30) - E2G (E15-29) | L-W - L-R | Mass air flow meter | Idling, Shift lever position P or N, A/C switch OFF | 0.5 to 3.0 V |
| THA (E15-22) - E2 (E15-28) | L-B - BR | Intake air temperature sensor | Idling, Intake air temperature 20°C (68°F) | 0.5 to 3.4 V |
| THW (E15-21) - E2 (E15-28) | B - BR | Engine coolant temperature sensor | Idling, Engine coolant temperature 80°C (176°F) | 0.2 to 1.0 V |
| VTA1 (E15-20) - E2 (E15-28) | B-R - BR | Throttle position sensor (for engine control) | Ignition switch ON, Throttle valve fully closed | 0.5 to 1.2 V |
| VTA1 (E15-20) - E2 (E15-28) | B-R - BR | Throttle position sensor (for engine control) | Ignition switch ON, Throttle valve fully open | 3.2 to 4.8 V |
| VTA2 (E15-19) - E2 (E15-28) | LG - BR | Throttle position sensor (for sensor malfunction detection) | Ignition switch ON, Accelerator pedal released | 2.1 to 3.1 V |
| VTA2 (E15-19) - E2 (E15-28) | LG - BR | Throttle position sensor (for sensor malfunction detection) | Ignition switch ON, Accelerator pedal depressed | 4.5 to 5.0 V |
| VPA (E14-18) - EPA (E14-20) | W-L - BR-W | Accelerator pedal position sensor (for engine control) | Ignition switch ON, Accelerator pedal released | 0.5 to 1.1 V |
| VPA (E14-18) - EPA (E14-20) | W-L - BR-W | Accelerator pedal position sensor (for engine control) | Ignition switch ON, Accelerator pedal depressed | 2.6 to 4.5 V |
| VPA2 (E14-19) - EPA2 (E14-21) | GR-G - BR-Y | Accelerator pedal position sensor (for sensor malfunctioning detection) | Ignition switch ON, Accelerator pedal released | 1.2 to 2.0 V |
| VPA2 (E14-19) - EPA2 (E14-21) | GR-G - BR-Y | Accelerator pedal position sensor (for sensor malfunctioning detection) | Ignition switch ON, Accelerator pedal depressed | 3.4 to 5.0 V |
| VCPA (E14-26) - EPA (E14-20) | LG-R - BR-W | Power source of accelerator pedal position sensor (for VPA) | Ignition switch ON | 4.5 to 5.5 V |
| VCP2 (E14-27) - EPA2 (E14-21) | BR-R - BR-Y | Power source of accelerator pedal position sensor (for VPA2) | Ignition switch ON | 4.5 to 5.5 V |
| HA1A (E16-2) - E04 (E16-7) HA2A (E16-1) - E05 (E16-6) |
Y - W-B R-L - W-B |
A/F sensor heater | Idling | Pulse generation (see waveform 2) |
| HA1A (E16-2) - E04 (E16-7) HA2A (E16-1) - E05 (E16-6) |
Y - W-B R-L - W-B |
A/F sensor heater | Ignition switch ON | 9 to 14 V |
| A1A+ (E16-22) - E1 (E17-1) | B - BR | A/F sensor | Ignition switch ON | 3.3 V *1 |
| A2A+ (E16-23) - E1 (E17-1) | G - BR | A/F sensor | Ignition switch ON | 3.3 V *1 |
| A1A- (E16-30) - E1 (E17-1) | W - BR | A/F sensor | Ignition switch ON | 3.0 V *1 |
| A2A- (E16-31) - E1 (E17-1) | R - BR | A/F sensor | Ignition switch ON | 3.0 V *1 |
| HT1B (E15-1) - E1 (E17-1) HT2B (E16-5) - E1 (E17-1) |
G - BR L - BR |
Heated oxygen sensor heater | Idling | Below 3.0 V |
| HT1B (E15-1) - E1 (E17-1) HT2B (E16-5) - E1 (E17-1) |
G - BR L - BR |
Heated oxygen sensor heater | Ignition switch ON | 9 to 14 V |
| OX1B (E15-18) - E2 (E15-28) OX2B (E16-33) - E2 (E15-28) |
W - BR B - BR |
Heated oxygen sensor | Maintain engine speed at 2,500 rpm for 2 minutes after warming up | Pulse generation (see waveform 3) |
| #10 (E17-2) - E01 (E15-7) #20 (E17-3) - E01 (E15-7) #30 (E17-4) - E01 (E15-7) #40 (E17-5) - E01 (E15-7) #50 (E17-6) - E01 (E15-7) #60 (E17-7) - E01 (E15-7) |
L - W-B G - W-B R - W-B W - W-B L - W-B Y - W-B |
Injector | Ignition switch ON | 9 to 14 V |
| #10 (E17-2) - E01 (E15-7) #20 (E17-3) - E01 (E15-7) #30 (E17-4) - E01 (E15-7) #40 (E17-5) - E01 (E15-7) #50 (E17-6) - E01 (E15-7) #60 (E17-7) - E01 (E15-7) |
L - W-B G - W-B R - W-B W - W-B L - W-B Y - W-B |
Injector | Idling | Pulse generation (see waveform 4) |
| IGT1 (E15-8) - E1 (E17-1) IGT2 (E15-9) - E1 (E17-1) IGT3 (E15-10) - E1 (E17-1) IGT4 (E15-11) - E1 (E17-1) IGT5 (E15-12) - E1 (E17-1) IGT6 (E15-13) - E1 (E17-1) |
R - BR R-L - BR G-B - BR G - BR B-L - BR P-L - BR |
Ignition coil (ignition signal) | Idling | Pulse generation (see waveform 7) |
| KNK1 (E16-29) - EKNK (E16-28) | B - W | Knock sensor | Maintain engine speed at 4,000 after warming up | Pulse generation (see waveform 5) |
| KNK2 (E16-21) - EKN2 (E16-20) | R - G | Knock sensor | Maintain engine speed at 4,000 after warming up | Pulse generation (see waveform 5) |
| VV1+ (E17-19) - VV1- (E17-29) | R - G | Variable valve timing (VVT) sensor | Idling | Pulse generation (see waveform 6) |
| VV2+ (E17-18) - VV2- (E17-28) | Y - L | Variable valve timing (VVT) sensor | Idling | Pulse generation (see waveform 6) |
| NE+ (E17-21) - NE- (E17-20) | B - W | Crankshaft position sensor | Idling | Pulse generation (see waveform 6) |
| IGF1 (E15-24) - E1 (E17-1) | G-R - BR | Ignition coil (ignition confirmation signal) |
Ignition switch ON | 4.5 to 5.5 V |
| IGF1 (E15-24) - E1 (E17-1) | G-R - BR | Ignition coil (ignition confirmation signal) |
Idling | Pulse generation (see waveform 7) |
| PRG (E15-34) - E1 (E17-1) | L - BR | VSV for EVAP | Ignition switch ON | 9 to 14 V |
| PRG (E15-34) - E1 (E17-1) | L - BR | VSV for EVAP | Idling | Pulse generation (see waveform 8) |
| SPD (E13-8) - E1 (E17-1) | V-R - BR | Speed signal from combination meter | Ignition switch ON, Rotate driving wheel slowly | Pulse generation (see waveform 9) |
| STA (E17-11) - E1 (E17-1) | B-Y - BR *2 L-Y - BR *3 |
Starter signal | Cranking | 9 to 14 V |
| NSW (E16-8) - E1 (E17-1) | L-Y - BR | Park/Neutral position switch signal | Ignition switch ON, Other shift position not in P or N | 9 to 14 V |
| NSW (E16-8) - E1 (E17-1) | L-Y - BR | Park/Neutral position switch signal | Ignition switch ON, Shift position in P or N | 0 to 3.0 V |
| STP (E14-15) - E1 (E17-1) | G-W - BR | Stop light switch | Brake pedal depressed | 7.5 to 14 V |
| STP (E14-15) - E1 (E17-1) | G-W - BR | Stop light switch | Brake pedal released | Below 1.5 V |
| ST1- (E14-16) - E1 (E17-1) | R-L - BR | Stop light switch (ST1 terminal status is opposite to STP terminal) |
Ignition switch ON, Brake pedal depressed | Below 1.5 V |
| ST1- (E14-16) - E1 (E17-1) | R-L - BR | Stop light switch (ST1 terminal status is opposite and STP terminal) |
Ignition switch ON, Brake pedal released | 7.5 to 14 V |
| M+ (E15-5) - ME01 (E16-3) | B - W-B | Throttle actuator | Idling with warm engine | Pulse generation (see waveform 10) |
| M- (E15-4) - ME01 (E16-3) | W - W-B | Throttle actuator | Idling with warm engine | Pulse generation (see waveform 11) |
| FC (E14-10) - E1 (E17-1) | LG-B - BR | Fuel pump control | Ignition switch ON | 9 to 14 V |
| FPR (E17-30) - E1 (E17-1) | P-L - BR | Fuel pump control | Ignition switch ON, STA signal OFF | 0 to 3.0 V |
| FPR (E17-30) - E1 (E17-1) | P-L - BR | Fuel pump control | Ignition switch ON, STA signal ON | 9 to 14 V |
| W (E13-30) - E1 (E17-1) | R-B - BR | MIL | Ignition switch ON | Below 3.0 V |
| W (E13-30) - E1 (E17-1) | R-B - BR | MIL | Idling | 9 to 14 V |
| TC (E14-23) - E1 (E17-1) | P-B - BR | Terminal TC of DLC3 | Ignition switch ON | 9 to 14 V |
| SIL (E14-30) - E1 (E17-1) | R-Y - BR | Terminal SIL of DLC3 | Connect intelligent tester to DLC3 | Pulse generation |
| TACH (E13-1) - E1 (E17-1) | B-W - BR | Engine speed | Idling | Pulse generation (see waveform 12) |
| ACIS (E15-33) - E1 (E17-1) | G-B - BR | VSV for ACIS | Ignition switch ON | 9 to 14 V |
| PSW (E17-10) - E1 (E17-1) | G-Y - BR | Power steering pressure switch | Ignition switch ON | 9 to 14 V |
Tech Tips
*1: The ECM terminal voltage is constant regardless of the output voltage from the sensor.
*2: A/T
*3: M/T
WAVEFORM 1
Camshaft timing Oil Control Valve (OCV)
| Item | Content |
|---|---|
| Symbols (Terminal No.) | OC1+ (E17-17) - OC1- (E17-16) OC2+ (E17-15) - OC2- (E17-14) |
| Tool Setting | 5 V/DIV., 1 msec./DIV. |
| Condition | Idling |
Tech Tips
The wavelength becomes shorter as the engine rpm increases.
WAVEFORM 2
A/F sensor heater
| Item | Content |
|---|---|
| Symbols (Terminal No.) | HA1A (E16-2) - E04 (E16-7) HA2A (E16-1) - E05 (E16-6) |
| Tool Setting | 5 V/DIV., 10 msec./DIV. |
| Condition | Idling |
WAVEFORM 3
Heated oxygen sensor
| Item | Content |
|---|---|
| Symbols (Terminal No.) | OX1B (E15-18) - E2 (E15-28) OX2B (E16-33) - E2 (E15-28) |
| Tool Setting | 0.2 V/DIV., 200 msec./DIV. |
| Condition | Engine speed maintained at 2,500 rpm for 2 minutes after warming up engine |
Tech Tips
In the Data List, item O2S B1S2 shows the ECM input values from the heated oxygen sensor.
WAVEFORM 4
Fuel injector
| Item | Content |
|---|---|
| Symbols (Terminal No.) | #10 (E17-2) - E01 (E15-7) #20 (E17-3) - E01 (E15-7) #30 (E17-4) - E01 (E15-7) #40 (E17-5) - E01 (E15-7) #50 (E17-6) - E01 (E15-7) #60 (E17-7) - E01 (E15-7) |
| Tool Setting | 30 V/DIV., 20 msec./DIV. |
| Condition | Idling |
Tech Tips
The wavelength becomes shorter as the engine rpm increases.
WAVEFORM 5
Knock sensor
| Item | Content |
|---|---|
| Symbols (Terminal No.) | KNK1 (E16-29) - EKNK (E16-28) KNK2 (E16-21) - EKN2 (E16-20) |
| Tool Setting | 0.01 to 10 V/DIV., 0.01 to 10 msec./DIV. |
| Condition | Maintain engine speed at 4,000 rpm after warming up engine |
Tech Tips
The wavelength becomes shorter as the engine rpm increases.
The waveform and amplitude displayed differ slightly depending on the vehicle.
WAVEFORM 6
(a) Crankshaft position sensor
(b) VVT sensor bank 1
(c) VVT sensor bank 2
| Item | Content |
|---|---|
| Symbols (Terminal No.) | NE+ (E17-21) - NE- (E17-20) VV1+ (E17-19) - VV1- (E17-29) VV2+ (E17-18) - VV2- (E17-28) |
| Tool Setting | 5 V/DIV., 20 msec./DIV. |
| Condition | Idling |
Tech Tips
The wavelength becomes shorter as the engine rpm increases.
WAVEFORM 7
(a) Igniter IGT signal (from ECM to igniter)
(b) Igniter IGF signal (from igniter to ECM)
| Item | Content |
|---|---|
| Symbols (Terminal No.) | IGT1 (E15-8) - E1 (E17-1) IGT2 (E15-9) - E1 (E17-1) IGT3 (E15-10) - E1 (E17-1) IGT4 (E15-11) - E1 (E17-1) IGT5 (E15-12) - E1 (E17-1) IGT6 (E15-13) - E1 (E17-1) IGF1 (E15-24) - E1 (E17-1) |
| Tool Setting | 2 V/DIV., 20 msec./DIV. |
| Condition | Idling |
Tech Tips
The wavelength becomes shorter as the engine rpm increases.
WAVEFORM 8
VSV for EVAP
| Item | Content |
|---|---|
| Symbols (Terminal No.) | PRG (E15-34) - E1 (E17-1) |
| Tool Setting | 10 V/DIV., 20 msec./DIV. |
| Condition | Idling |
Tech Tips
If the waveform is not similar to the illustration, check the waveform again after idling for 10 minutes or more.
WAVEFORM 9
Vehicle speed signal
| Item | Content |
|---|---|
| Symbols (Terminal No.) | SPD (E13-8) - E1 (E17-1) |
| Tool Setting | 2 V/DIV., 20 msec./DIV. |
| Condition | Driving at 20 mph (12 km/h) |
Tech Tips
The wavelength becomes shorter as the vehicle speed increases.
WAVEFORM 10
Throttle actuator positive terminal
| Item | Content |
|---|---|
| Symbols (Terminal No.) | M+ (E15-5) - ME01 (E16-3) |
| Tool Setting | 5 V/DIV., 1 msec./DIV. |
| Condition | Idling with warm engine |
Tech Tips
The duty ratio varies depending on the throttle actuator operation.
WAVEFORM 11
Throttle actuator negative terminal
| Item | Content |
|---|---|
| Symbols (Terminal No.) | M- (E15-4) - ME01 (E16-3) |
| Tool Setting | 5 V/DIV., 1 msec./DIV. |
| Condition | Idling with warm engine |
Tech Tips
The duty ratio varies depending on the throttle actuator operation.
WAVEFORM 12
Engine speed signal
| Item | Content |
|---|---|
| Symbols (Terminal No.) | TACH (E13-1) - E1 (E17-1) |
| Tool Setting | 5 V/DIV., 10 msec./DIV. |
| Condition | Idling |
Tech Tips
The wavelength becomes shorter as the engine rpm increases.